Railway car retarder



7, 193? J. W. LIVINGSTON RAILWAY CAR RETARDER Filed July 9, 1935 5 Sheets-Sheet l IN VE!\ITOR John WLwmgstan.

HIS

ATTORNEY ZJGLEM:

Dec. 7, 393?. J. W. LIVINGSTON RAILWAY CAR RETARDER Filed July 9, 1955 5 Sheets-Sheet 2 HIS ATTORN EY ZAMQWQ Dec, 7, 19370 J. W. LWHNGSTON RAILWAY CAR RETARDER Filed July 9, 1935 5 Sheets-Sheet 3 INVENTOR WLwz'ngszon H55 ATTORNEY Patented Dec. 7, 1937 UNITED STATES RAILWAY CAR RETARDER John W. Livingston, Wilkinsburg, Pa., assignor to The Union Switch &' Signal Company, Swissvale, Pa, a corporation of Pennsylvania Application July, 9, 1935, Serial No. 30,528

24 Claims.

My invention relates to railway car retarders, and particularly to car retarders of the track brake type used in classification or hump yards of railroads for controlling the speed of cars.

One object of my invention is the provision of improved apparatus for automatically controlling the braking action of a car retarder of the type described in accordance with the speed of cars approaching or passing through the retarder.

I will describe two forms of car retarder controlling apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view illustrating one form of apparatus embodying my invention. Fig. 2 is a lefthand end View of the timing unit U forming part of the apparatus illustrated in Fig 1. Fig. 3 is 2 a vertical sectional view of a portion of the timing unit U shown in Fig. 2. Fig. 4 is an enlarged end View or" the contact mechanism D forming part of the timing unit U shown in Figs. 2 and 3. Fig. 5 a diagrammatic View illustrating another form of car retarder controlling apparatus embodying my invention.

Similar reference characters refer to similar parts in all five views.

Referring first to Fig. l, the reference characters l and l designate the track rails of a stretch of railway track over which cars normally move in the direction indicated by the arrow under such conditions that it is desirable to at times contrcl the speed of the cars automatically. For example, the stretch of track here shown might be in a classification yard of the hump, type through which cars move under the influence of gravity. It is obvious that in service of this kind, the speed of individual cars or strings of cars 4o will vary through wide limits, depending, among other things, upon the speed at which they go over the hump, the temperature, the weight of the car and its contents, and the condition or the car as to whether it is a free running car or otherwise.

In order to control the speed of the cars, the stretch of track illustrated in the drawings is provided with a car retarder R which, in the form here shown, comprises two braking bars 2 and 3 extending parallel with, and located on opposite sides of, rail l, and two similar braking bars 2 and 3* extending parallel with, and located on opposite sides of, rail l The braking bars of each pair are so disposed that when they are 5.3. moved toward the associated rail, they will occupy artist PATENT i iiijh positions in which they will engage the wheels or other parts of a passing car, and will thus retard the speed of the car.

The car retarder R is operated by a mechanism M which is controlled by a relay C and by a 5 lever L. The construction of the mechanism M, and the manner in which this mechanism is controlled by the relay C and lever L forms no part of my present invention, and may, for example, be similar to that shown in Letters Patent of the United States No. 1,958,293, granted to Herbert L. Bone and myself, on May 8, 1934. It is believed, therefore, that for purposes of my present invention, it is suflicient to state that when relay C is deenergized, the operating mechanism will move the braking bars to their braking or non-braking positions according as lever L occupies its right-hand or on position in which it is shown in the drawings, or its left-hand or off position, but that, when relay C becomes energized, ii the braking bars do not already occupy their non-braking positions, the mechanism M will automatically move them to their nonbraking positions.

In accordance with my present invention novel and improved means are provided for controlling relay C in such manner that this relay will become energized automatically when the speed of a car which is traversing the stretch of track shown in the drawing falls below a speed which depends upon the setting of a manually operable speed control lever S. As here shown, these means comprise a series of relatively short insulated control sections 4 4 i etc., which are formed in the rail 1. These control sections will usually be of uniform length, and their lengths may be varied as conditions require, but the lengths of these sections will preferably be such that two wheels of a car can not occupy the same section at any one time.

The means for controlling relay C also comprise a plurality of timing units one of which is associated with each control section t, and each of which is designated as a, whole by the reference character U with a suitable distinguishing exponent. These timing units are similar, and a description of one will therefore suffice for all. Referring particularly to the timing unit U shown in detail in Figs. 2 and 3, this timing unit comprises a driving electromagnet A and a holding electromagnet B. These electromagnets are similar and each comprises a magnetizable core 6 provided with a centrally located hole 1, and with an annular recess 8 in one side, which recess is concentric with the hole I, and which recess receives a winding 9. The two electromagnets A and B are secured, in axial spaced relation, to a fixed support not shown in the drawings in such manner that the sides in which the recesses 8 are formed face each other, and extending with considerable clearance through the holes in these electromagnets is a driveshaft M, This driveshaft cooperates with all of the timing units U as will be apparent from an inspection of Fig. 1, and is driven at a constant speed in a clockwise direction, as viewed in Fig. 2, by an electric motor N shown diagrammatically in Fig. 1. Surrounding the driveshaft ll between the electromagnets A and B are a driving disk 52 provided with a hub is which is keyed to the driveshaft H in a fixed position, and a magnetizable cam disk I provided with a hub 15 which is loosely mounted on the driveshaft i l. The hub it extends with some clearance through the hole '5 in the core 6 of the electromagnet A, and the hub i5 similarly extends with some clearance through the hole I in the core 6 of the electromagnet B. It will be seen, therefore, that the driving disk 62 is constantly rotated with the driveshaft, but that, the cam disk I 4 is free to rotate independently of the driveshaft. A spiral spring I5 is secured at one end to the hub E5 of the cam disk M, and at the other end to a support EB, and this spring constantly biases the cam disk id in a counterclockwise direction, as viewed in Fig. 2, to a position in which a, stop lug ll formed on the cam disk engages a stop member l8 secured to a contact bracket 59. The spring it also biases the cam disk Hi to the longitudinal position 011 the driveshaft H in which this cam disk is midway between a clutch facing 20 secured to the driving disk l2 and a clutch facing 2i secured to an annular flange 22 formed on the core 5 of electromagnet B. The parts are so proportioned that when electromagnet A is energized, this electromagnet will exert a magnetic pull on the cam disk M which will cause the cam disk to slide longitudinally along the driveshaft to a position in which it frictionally engages the clutch facing 28 with sumcient force to cause the cam disk to rotate with the driving disk, in opposition to the bias of the spring It, and that, when the electromagnet B is energized, this latter electromagnet will exert a magnetic pull on the cam disk which will cause it to slide longitudinally along the driveshaft H to a position in which it frictionally engages the clutch facing 21 with sufficient force to hold the cam disk, in opposition to the bias of the spring H5, in any position to which it had been previously rotated by engagement with the driving disk !2.

The timing mechanism U also comprises a plurality of contact mechanisms, one of which is provided for each control speed at which it is desired to have cars leave the retarder. As here shown, three such mechanisms are provided, one for high speed, one for medium speed, and one for slow speed, these mechanisms being designated by the reference characters D D and D respectively. These contact mechanisms are mounted on the contact support 59 at spaced points around the periphery of the cam disk M, and in the form here illustrated, each of these mechanisms comprises a flexible contact finger 25 secured at one end to an insulating terminal block 29 by means of a terminal post as, and provided intermediate its ends with a roller 3i which cooperates with a cam lobe M formed on the cam disk M. The free end of each contact finger 25 is trifurcated, and cooperates with three fixed contact members 25,

21 and 28 (see Fig. 4) in such manner that when the cam lobe M on the cam disk I4 is out of engagement with the associated roller 3|, the middle trifurcation will engage the contact member 25 and will thus close a back contact 25-46, but that, when the cam lobe I l is engaging the roller, the two outside trifurcations will then enga e the fixed contact members 2'! and 2B and will thus close front contacts 25-21 and 25-28. The fixed contact members 26, 21- and 28 are secured to the contact block 29 by means of terminal posts 32, 33 and 34, respectively. The location of the contact mechanisms D, D and D are such, and the parts are so proportioned that these mechanisms will become operated when the electromagnet A becomes energized if and only if the electromagnet A subsequently remains energized for time intervals which are equal to, or greater than, that required for a car to traverse a distance equal to the lengths of one of the control sections 4 when the car is traveling at the high, medium or low control speed, respectively, at which it is desired to have cars leave the retarder.

It is desirable to be able to readily inspect the contact mechanisms D D and D and for this purpose the contact bracket 19 is pivotally supported at its upper end on a hanger 35, and is secured at its lower end to the support ill by means of screws 35 in such manner that by releasing the screws 36 the entire contact assembly may be rotated away from the remainder of the timing unit.

The manually operable speed control lever S will usually be located adjacent the lever L in a position where it may be conveniently operated by the same operator who operates the lever L. As here shown, the lever S is provided with a high speed position s in which it is shown in the drawings, a medium speed position indicated by a dotted line in the drawings and designated by the reference character 8 and a low speed position also indicated by a dotted line in the drawings and designated by the reference character s Operatively connected with the lever S are a plurality of contact arms one of which is provided for each control section, and each of which is designated by the reference character 5 with a suitable distinguishing exponent. The contact arm 5* cooperates with three fixed contacts 5 5 and 5 to selectively close a contact 5* --5 S 45 or il -5 according as lever S occupies its 8 its s or its 8 position. Each of the other contact arms 5 similarly cooperates with three fixed contacts 5 5 and 5 to selectively close contacts in the same manner that the arm 5 cooperates with the fixed contacts 5 5 and 5 to selectively close the contacts 5 5 5* -5 and 5 -43 The electromagnet A of timing unit U is provided with a first energizing circuit which includes the winding of the electromagnet, a suitable source of current here shown as a battery E, rail I control section 4 contact 5 -5 of lever S, and contact 25-2i of the associated contact mechanism D This circuit becomes closed when and only when lever S occupies its 8 position and a car wheel moves onto control section 4 and it will be apparent that when this circuit becomes closed, electromagnet A of unit U will become energized and will cause the associated cam disk M to rotate in the manner previously described. It will also be apparent that when this circuit becomes closed, it will subsequently remain closed for a time interval which depends upon the speed of the car which caused it to become closed unless the speed of the car is equal to, or less than, that corresponding to the 3 position of lever S, in which event cam disk 14 will operate contact mechanism D thus causing contact 25-2-6 to open and deenergize electromagnet A.

Electromagnet A of timing unit U is also provided with a second energizing circuit which is similar to the first energizing circuit described above with the exception that this circuit ineludes in place of contact 5 -5 of lever S and contact 25-28 of the associated contact mechanism D contact Fa -5 of lever S and contact 25-46 of the associated contact mechanism D This circuit becomes closed when and .onlywhen lever S occupies its s position and a car wheel moves onto control section A and it will be apparent that when this circuit becomes closed, the electromagnet A of unit U will become energized and will cause cam disk M to rotate in the manner previously described. It will also be apparent that when this circuit becomes closed, it will subsequently remain closed for a time interval which depends on the speed of the car unless the speed of the car is equal to, or less than, that corresponding to the 8 position of the lever S in which event the cam disk It will operate the contact mechanism D thus causing contact 25-26 to open and deenergize electromagnet A.

Electromagnet A of timing unit U is further provided with a third energizing circuit which is similar to the first energizing circuit with the exception that this third circuit includes contact 5 -5 of lever S and contact 25-2ii of the associated contact mechanism D in place of contact E -5 of leverS and contact 25- 5 or" the associated contact mechanism D This latter circuit becomes closed when and only when lever S occupies its 5 position and a car wheel enters section 4 and it will be apparent that when this circuit becomes closed, electromagnet A will become energized and will thus cause cam disk i l to rotate in the manner previously described. It will also be apparent that when this circuit becomes closed, it will subsequently remain closed for a time interval which depends upon the speed of the car unless the speed of the car is then equal to, or less than, that corresponding to the 5 position of the lever in which event cam disk M will operate contact mechanism D thus causing contact 25-25 to open and deenergize electromagnet A.

The electromagnet B of timing unit U is provided with a first energizing circuit which includes the winding of the .electromagnet, battery E, rail l control section 3 contact 5 -5 of lever S, and contact 25-28 of the associated contact mechanism D This circuit becomes closed when and only when lever S occupies its s position and the speed of a car whose wheel is traversing section 4* is sufiiciently slow to cause the contact mechanism D to become operated, and it will be apparent that when this circuit becomes closed, electromagnet B will become energized. It will also be. apparent that when electromagnet B becomes energized, contact mechanism D will be held in its operated position in the manner previously described, with the result that after electromagnet B has once become energized under these conditions, it will subsequently remain energized until the car wheel which caused it to become energized departs from section 4 Electromagnet B of timing unit U is also provided with a second energizing circuit which is similar to the circuit just described with the exception that this latter circuit includes, in place of contact 5 -5 of lever S and contact 25-48 of the associated contact mechanism D contact 5 -5 of lever S and contact 2528 of the associated contact mechanism D This circuit becomes closed when and only when lever S occupies its 8 position and the speed of a car whose wheel is traversing section 4 is sufficiently slow to cause the contact mechanism D to become operated, and it will be apparent that when this circuit becomes closed, electromagnet B will become energized. It will also be apparent that when electromagnet B becomes energized, this electromagnet will subsequently remain energized and will hold the contact mechanism D in its operated position until the car wheel, which caused the electromagnet to become. energized, departs from the control section 4*.

Electromagnet B of timing unit U is further provided with a third energizing circuit which is similar to the first energizing circuit with the exception that this circuit includes, in place of contact 5 "*5 of lever S and contact 25-28 of the associated contact mechanism D contact 5 5 of lever S and contact 25-28 of the associated contact mechanism D This circuit becomes closed when and only when lever S occupies its 5 position and the speed of a car whose wheel is traversing section i is sufficiently slow to cause the contact mechanism D to become operated, and it will be apparent that When this circuit becomes closed, electromagnet B will become energized. It will also be apparent that when this circuit becomes closed, it will subsequently remain closed until the car wheel which caused it to become closed departs from section 4 The electromagnets A and B of each of the remaining timing units are each provided with circuits which are similar to those just described for the electromagnets A and B of timing unit U Since these circuits are similar to those previously described, it is believed that they will be obvious from an inspection of the drawings without further description.

The control relay C is provided with a first.

series of control circuits, which circuits are rendered effective for controlling relay C when and only when lever S occupies its 8 position, and each of which includes the contact 25-2! of the contact mechanism D of a different one of the timing units U. These control circuits are similar and a description of one will therefore sufiice for all. Referring particularly to the control circuit which includes the contact 2521 of the contact mechanism D of unit U this circuit includes battery E, rail I control section 4 contact fi -5 of lever S, contact 25-2"! of contact mechanism D wires 4% and ll, winding of relay C and wire 42. It will be apparent, therefore, that when lever S occupies its s position and a car wheel traverses any one of the control sections t at a speed which is sufliciently slow to cause the associated contact mechanism D to become operated, the resultant closing of the contact 252l of such contact mechanism will complete the control circuit for relay C including this contact, and relay C will therefore become energized.

The control relay C is also provided with a second series of control circuits which are rendered effective for controlling this relay when and only when lever S occupies its .9 position, and each of which includes the contact 25-21 of the contact mechanism D of a different one or the timing units U. Referring particularly to the control circuit for relay C which includes the contact 2521 of the contact mechanism D of unit U this circuit also includes a battery E, rail I, control section 4*, contact 5 5 of lever S, wires 43, 45 and 4|, winding of relay C and wire 42. Each of the remaining control circuits of the series is similar to that just described and will be obvious from an inspection of the drawings. It will be apparent, therefore, that when lever S occupies its s position and a car wheel traverses any one of the control sections 4 at a speed which is sufiiciently slow to cause the associated contact mechanism D to become operated, the resultant closing of the contact 2521 of such control mechanism will complete the circuit for relay C including this contact and relay C will therefore become energized.

The control relay C is further provided with a third series of control circuits which are rendered effective for controlling this relay when and only when lever S occupies its s position, and each of which includes the contact 25-2'l of the contact mechan sm D of a different one of the timing units U. Referring particularly to the control circuit for relay C which includes contact 2'5-2l of the contact mechanism D of the unit U this circuit also includes battery E, rail l control section 4 contact 5 5 of lever S, wires 44, 45 and 4! the winding of relay C and wire 42. Each of the other control circuits of the series is similar to that just described and will be obvious from an inspection of the drawings. It will be apparent, therefore, that when lever S occupies its 3 position and a car wheel traverses any one of the control sections 4 at a speed which is sufficiently slow to cause the associated contact mechanism D to become operated, the resultant closing of the contact 25-2'| of such contact mechanism will complete the control circuit for relay C including this contact and relay C will therefore become energized.

Relay C is made sufficiently slow releasing so that when a car is traversing the stretch of track shown in the drawings at a speed which is just .slow enough to cause the contact mechanisms D of the timing units U to become successively operated, this relay will bridge the interval of time which will elapse under these conditions between the opening of the contact 25-41 of the contact mechanism D of one timing unit U due to a wheel of a car having departed from the associated control section 4, and the closing of the contact 25-21 of the contact mechanism D of the timing unit next in advance due to the same wheel of the car having moved onto the section 4 associated with this latter timing unit.

As shown in the drawings, all parts are in the positions which they normally occupy when it is desired to retard a car which is approaching the retarder from the left, to the highest speed for which the apparatus is designed. That is to say, lever S occupies its 8 position, the electromagnets A and B of each of the timing units U are deenergized, lever L occupies its on position, relay C is deenergized, and the braking bars occupy their braking positions.

With the parts in the positions just described, I will assume that a car which is traveling at a higher rate of speed than that for which the speed control lever S is set enters the retarder. As the car moves through the retarder, each time a car wheel moves onto one of the control sections 4, the electromagnet A of the associated timing unit U will become energized in the manner previously described, but as long as the speed of the car is above that corresponding to the 8 position of the lever, none of the electromagnets A will remain energized long enough to cause the associated contact mechanism D to become operated. Relay C will therefore remain deenergized, and the car retarder will therefore continue to slow down the car. As soon, however, as the car has been slowed down by the car retarder to a speed which is equal to, or less than, the speed corresponding to the s position of lever S, and a wheel of the car traverses any one of the control sections 4, the contact mechanism D of the associated timing unit U will then become operated and will close its contact 25-21, thus completing one of the previously described control circuits for relay C. Relay C will therefore become energized, and when this relay becomes energized, the braking bars will be moved to their non-braking positions by the operating mechanism M in the manner previously described. After the braking bars have once been moved to their non-braking positions, no further retardation of the car will take place unless the car again speeds up to a speed which is above that corresponding to the 5 position of lever S while the car is still within the limits of the retarder. Assuming that the car does this, then as soon thereafter as the contact mechanism D which last became operated is restored to its normal position and an interval of time equal to the release time of relay C has elapsed thereafter, relay C will become deenergized and will subsequently remain deenergized because, under these conditions, none of the other contact mechanisms D will subsequently become operated. As soon as relay C becomes deenergized, the braking bars of the car retarder R will, of course, again move to their braking positions and will start to again slow down the car. It will be seen, therefore, that when lever S occupies its 8 position and a car which is traveling at a higher control speed than that corresponding to this position of the lever enters the retarder, the car retarder will automatically retard the car in such manner as to cause it to leave the retarder at the control speed corresponding to the 5 position of the lever.

I will now assume that the operator has moved the speed control lever S to its 8 position and that a car which is traveling at a higher speed than that corresponding to this position of the lever enters the retarder. Under these conditions, the operation of the apparatus will be similar to that just described with the exception that the contact mechanisms D of the timing units will be rendered effective for controlling relay C, with the result that the braking bars will now slow down the car as long as the car speed is above that corresponding to the s position of the lever.

The operation of the apparatus, when lever S occupies its 8 position and a car traverses the stretch of track shown in the drawings, is similar to that described above when lever S occupied its s position and a car traversed the stretch oftrack shown in the drawings with the exception that, under these conditions, the contact mechanisms D of the timing units U are rendered effective for controlling relay C, and the braking bars will therefore slow down the car as long as the speed of the car is above that corresponding to the 8 position of the lever.

Referring now to Fig. 5, in the modified form of apparatus here illustrated the timing units U instead of each being. provided with three contact mechanisms: D D2, and D as shown in Fig; 1, are each provided with only one contact mechanism D and the shaft l I which drives the driving disks 12 of the timing units, instead of being. driven at a constant speed in the manner previously described, is arranged to be driven at a plurality of different speeds by means of a variable speed motor N the speed of which may be controlled by any of the well-known forms of speed-control devices. As here shown, the speed of the motor N is controlled by a speed controller SC comprising a speed control lever 59 which is movable to three positions s s and s and which controls the supply of energy to the motor N in such manner that the motor will be driven at a different speed in each different position of the speed control lever. Speed controllers of the type described are well-known, and it is believed, therefore, that for purposes of my present invention a more-detailed description of this speed controller isunnecessary.

With the'timing units arranged in the manner just described, it will be apparent that the time interval which will elapse after the electromagnet-A of a timing unitbecomes energized and before theassociated contact mechanism D becomes operated will vary with the setting of the speed control lever 50, and the parts are so proportioned that according as lever 58 occupies its s 8 or s position, these time intervals will be equal to those required for a car to traverse a distance equal to the lengths of one of the control sections 4 when the car is traveling at a high, medium, or lowcontrol speed, respectively.

The apparatus shown in Fig. 5 further differs from that shown in Fig. 1 in that the electromagnets A and B of the timing units U of the apparatus shown in Fig. 5 areeach provided with only one control circuit, thus rendering the use of the speed control lever S unnecessary. Referring particularly to the timing unit U the control circuit for electromagnet A of this timing unit includes battery E, rail l control section 4 contact 25-2ii of contact mechanism D and the winding of electromagnet A; while the control circuit for electromagnet B of the timing unit U includes battery E, rail l control section 4, contact 2528 of contact mechanism D and the winding of electromagnet B. It will be seen, therefore, that each time a car wheel moves onto. control section 4 electromagnet A of timing unit U will become energized and will subsequently remain energized until the car leaves the section unless the car is traveling at a speed which is sufficiently slow to cause contact mechanism D to become operated, whereupon electromagnet A will become deenergized and electromagnet B will become energized. It will also be seen that when electromagnet B once becomes energized, it will remain energized and will retain contact mechanism D in its operated position until the car Wheel which caused it to become energized subsequently leaves control section 4 The control circuits for the electromagnets A and B of each of the other timing units are similar to those just described for the electromagnets A and B of the timing unit U and the operation of the other units is likewise similar to the operation of the unit U Relay C is controlled by the contact mechanism D of each timing unit U in exactly the same manner as in Fig. l.

The operatic-n of the system as a Whole when constructed as shown in Fig. 5 is similar tothat of the system shown in Fig. 1 with the exception that the same contact mechanisms D function for all control speeds, and that the different control speeds are obtained by moving the speed control lever 5a to different positions, thus causing the contact mechanisms to operate at the expiration of different intervals of time in the manner previously described.

It should be pointed out that While, with the apparatus constructed as illustrated in Fig. 5, I have shown means for driving the shaft i at only three selected speeds, this shaft might equally well be driven by other well-known means in such manner that its speed could be continuously varied through wide limits, and that with such a means for driving the shaft, the speed at which cars will leave the retarder may be continuously varied through wide limits.

One advantage of a speed control system for railway car retarders embodying my invention is that, since the driving disks M of all of the timing units rotate at the same speed, and since the contact mechanisms are located at the same relative positions with respect to the associated driving disk on all of the units, the timing of all of the units will be uniform.

Another advantage of a speed control system for car retarders embodying my invention is that, since the timing of the timing units depends entirely upon the rotational speed of shaft D, the timing of each of the units may be simultaneously varied in a very simple manner by simply changing the speed of the shaft H.

A further advantage of a speed control system for car retarders embodying my invention is that, since the timing of the Whole system depends entirely on the rotational speed of the shaft II, and since this shaft is driven by a constantspeed motor, the timing of the system will not vary with variations in the ambient temperature. If, however, temperature compensation is desired to compensate for increases in car resistance at lower temperatures, a variable speed motor or a gear box can be used to accomplish the desired result.

Although I have herein shown and described only two forms of car retarder controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and a normally open contact, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contact when said memher is moved away from said one position a predetermined amount, an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position at a predetermined rate of speed, an energizing circuit for said electromagnet including said control section, the opposite rail of said stretch and said normally closed contact; and an electroresponsive device controlled by said normally open contact.

2. In combination, a stretch of railway track,

an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and a normally open contact, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contact when said member is moved away from said one position a predetermined. amount, an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position at a predetermined speed, an energizing circuit for said electromagnet including said control section, the opposite rail of said stretch and said normally closed contact; and means controlled by said normally open contact for controlling the speed of a car traversing said stretch.

3. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and a normally open contact, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contact when said member is moved away from said one position a predetermined amount, an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position at a predetermined speed, an energizing circuit for said electromagnet including said control section, the opposite rail of said stretch and said normally closed contact; a car retarder associated with said stretch for controlling the speed of a car traversing said stretch, and means for controlling said car retarder controlled by said normally open contact.

4. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and a normally open contact, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contact when said member is moved away from said one position a predetermined amount, an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position at a predetermined speed, an energizing circuit for said electromagnet including said control section, the opposite rail of said stretch and said normally closed contact; a slow acting relay controlled by said normally open contact, and means controlled by said relay for controlling the speed of a car traversing said stretch.

5. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and a normally open contact, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contact when said member is moved away from said one position a predetermined amount, an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position at a predetermined speed, an energizing circuit for said electromagnet including said control section, the opposite rail of said stretch and said normally closed contact, a relay; a circuit for said relay including said not" mally open contact, said control section, and the opposite rail of said stretch; and means controlled by said relay for controlling the speed of a car traversing said stretch.

6. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one posi-- tion, a contact mechanism including a normally closed and two normally open contacts, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contacts when said member is moved away from said one position a predetermined amount, a first electromagnet, means effective when said first electromagnet becomes energized for moving said member away from said one position at a predetermined speed; an energizing circuit for said first electromagnet including said control section, the

opposite rail of said stretch and said normally circuit for said second electromagnet including u said control section, the opposite rail of said stretch and one of said normally open contacts; and an electroresponsive device controlled by the other normally open contact.

7. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and two normally open contacts, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contacts when said member is moved away from said one position a predetermined amount, a first electromagnet, means effective when said first electromagnet becomes energized for moving said member away from said one position at a pre determined speed; an energizing circuit for said first electromagnet including said control section, the opposite rail of said stretch and said normally closed contact, a second electromagnet, means efiective when said second electromagnet becomes energized for holding said member in the position which it then occupies; an energizing circuit for said second electromagnet including said control section, the opposite rail of said stretch and one of said normally open contacts; and means controlled by the other normally open contact for controlling the speed of a car traversing said stretch.

8. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and two normally open contacts, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contacts when said member is moved away from said one position a pre-- determined amount, a first electromagnet, means effective when said first electromagnet becomes energized for moving said member away from said one position at a predetermined speed; an energizing circuit for said first electromagnet including said control section, the opposite rail of said stretch and said normally closed contact; a second electromagnet, means effective when said second electromagnet becomes energized for bolding said member in the position which it then occupies; an energizing circuit for said second electromagnet including said control section, the opposite rail of said stretch and one of said normally open contacts; a car retarder associated with said stretch, and means controlled by the other normally open contact for controlling said car retarder.

9. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and two normally open contacts, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contacts when said member is moved away from said one position a predetermined amount, a first electromagnet, means effective when said first electromagnet becomes energized for moving said member away from said one position at a predetermined speed; an energizing circuit for said first electromagnet including said control section, the opposite rail of said stretch and said normally closed contact; a second electromagnet, means effective when said second electromagnet becomes energized for holding said member in the position which it then occupies; an energizing circuit for said second electromagnet including said control section, the opposite rail of said stretch and one of said normally open contacts; a slow acting relay, a circuit for said relay including the other normally open contact, said control section, and the opposite rail of said stretch; and means controlled by said relay for controlling the speed of a car traversing said stretch.

10. In combination, a stretch of railway track, a series of insulated control sections formed in one rail of said stretch, a plurality of electromagnets one associated with each of said control sections, a plurality of cams one associated with each of said electromagnets and each biased, to one position, means associated with each electromagnet and effective when the associated electromagnet is, energized for moving the associated cam away from said one position at a predetermined speed, a plurality of contact mechanisms one associated with each cam and each including a normally closed contact which becomes opened and a normally open contact which becomes closed when the associated cam has been moved away from its said one position a predetermined distance, a series of control circuits one for each electromagnet and each including the normally closed contact of the associated contact mechanism, a difierent one of said insulated control sections and the opposite rail of said stretch, and an electroresponsive device controlled by said normally open contacts.

11. In combination, a stretch of railway track, a braking bar located in the trackway adjacent one of the rails of said stretch and movable into engagement with a part of a car traversing said stretch for retarding the speed of the car, a plurality oi. electromagnets, a plurality of cams one associated with each of said electromagnets and each biased to one position, means associated with each electromagnet and effective when the associated electromagn-et is energized for moving the associated cam, away from said one position at a predetermined speed, a plurality of contact mechanisms one associated with each cam and each including a normally closed contact which becomes opened and a normally open contact which becomes closed when the'associated cam has been moved away from its said one position a predetermined distance, a series of insulated control sections formed in one rail of said stretch; a series of control circuits one for each electromagnet and each including the normally closed contact of the associated contact mechanism, a different one of said insulated control sections and the opposite rail of said stretch; and means controlled by said normally open contact for controlling the braking action of said braking bar.

12. In combination, a stretch of railway track, a braking bar located in the trackway adjacent one of the rails of said stretch and movable into engagement with a part of a car traversing said stretch for retarding the speed of the car, a plurality of electromagnets, a plurality of cams one associated with each of said electromagnets and each biased to one position, means associated with each electromagnet and effective when the associated electromagnet is energized formoving the associated cam away from said one position at a predetermined speed, a plurality of contact mechanisms one associated with each cam and each including a normally closed contact which becomes opened and a normally open contact which becomes closed when the associated cam has been moved away from its said one position a predetermined distance, a series of insulated control sections formed in one rail of said stretch; a series of control circuits one for each electromagnet and each including the normally closed contact of the associated contact mechanism, a different one of said insulated control sections and the opposite rail of said stretch; a relay, a plurality of control circuits for said relay each including a different one of said normally open contacts, the associated control section, and the opposite rail of said stretch, and means controlled by said relay for controlling the braking action of said car retarder.

13. In combination, a stretch of railway track,

a series of insulated control sections formed in one rail of said stretch, a braking bar located in the trackway adjacent one of the rails of said stretch and movable into engagement with a part of a car traversing said stretch for retarding the speed of the car; a series of timing units one associated with each control section and each including a cam biased to one position, a contact mechanism controlled by said cam and including a normally closed contact which becomes opened and two normally open contacts which become closed when said cam is moved a predetermined distance away from said one position, a first electromagnet, means effective when said first electromagnet is energized for moving said cam away from said one position at a predetermined speed, a second electromagnet, and means effective when said second electromagnet becomes energized for retaining said cam in the position which it then occupies; a first series of energizing circuits one for the first electromagnet of each timing unit and each including the normally closed contact of the associated contact mechanism, the associated control section and the opposite rail of said stretch; a second series of energizing circuits one for the second electromagnet of each timing unit and each' including one of the normally open contacts of the associated contact mechanism, the associated control section and the opposite rail of said stretch, and means controlled by the other normally open contacts for controlling said braking bar.

14. In combination, a stretch of railway track, a series of insulated control sections formed in one rail of said stretch, a braking bar located in the trackway adjacent one of the rails of said stretch and movable into engagement with a part of a car traversing said stretch for retarding the speed of the car; a series of timing units one associated with each control section and each including a cam biased to one position, a contact mechanism controlled by said cam and including a normally closed contact which becomes opened and two normally open contacts which become closed when said cam is moved a predetermined distance away from said one position, a first electromagnet, means efiective when said first electromagnet is energized for moving said cam away from said one position at a predetermined speed, a second electromagnet, and means effective when said second electromagnet becomes energized for retaining said cam in the position which it then occupies; a first series of energizing circuits one for the first electromagnet of each timing unit and each including the normally closed contact of the associated contact mechanism, the associated control section and the opposite rail of said stretch; a second series of energizing circuits one for the second electromagnet of each timing unit and each including one of the normally open contacts of the associated contact mechanism, the associated control section and the opposite rail of said stretch, a relay; a series of control circuits for said relay each including the other normally open contact of a different one of said timing units, the associated control section, and the opposite rail of said stretch; and means controlled by said relay for controlling said braking bar.

15. In combination, a stretch of railway track, a series of insulated control sections formed in one rail of said stretch, a braking bar located in the trackway adjacent one of the rails ofsaid stretch and movable into engagement with a part of a car traversing said stretch for retarding the speed of the car; a series of timing units one associated with each control section and each including a cam biased to one position, a first electromagnet, means effective when said first electromagnet is energized for moving said cam away from said one position at a predetermined rate of speed, a second electromagnet, means effective when said second electromagnet becomes energized for holding said cam in the position which it then occupies, and a plurality of contact mechanisms each adapted to be operated by movement of said cam a different distance away from said one position and each including a normally closed contact which becomes opened and two normally open contacts which become closed when the mechanism is operated; a speed control lever movable to a plurality of different positions and provided with a plurality of contacts one for each section for each position of the lever; a plurality of circuits for the first electromagnet of each timing unit each including the normally closed contact of a difierent one of the associated contact mechanisms, a different one of the associated lever contacts, the associated control section, and the opposite rail of said stretch, a plurality of circuits for the second electromagnet of each timing unit each including one of the normally open contacts of a different one of the associated contact mechanisms, a diiferent one of the associated lever contacts, the associated control section, and the opposite rail of said stretch; and means controlled in part by the other normally open contact of said contact mechanisms for controlling said braking bar.

16. In combination, a stretch of railway track, a series of insulated control sections formed in one rail of said stretch, a braking bar located in the trackway adjacent one of the rails of said stretch and movable into engagement with a part of a car traversing said stretch for retarding the speed of the car; a series of timing units one associated with each control section and each including a cam biased to one position, a first electromagnet, means efiective when said first electromagnet is energized for moving said cam away from said one position at a predetermined rate of speed, a second electromagnet, means effective when said second electromagnet becomes energized for holding said cam in the position which it then occupies, and a plurality of contact mechanisms each adapted to be operated by movement of said cam a difierent distance away from said one position and each including a normally closed contact which becomes opened and two normally open contacts which become closed when the mechanism is operated; a speed control lever movable to a plurality of different positions and provided with a plurality of contacts one for each section for each position of the lever; a plurality of circuits for the first electromagnet of each timing unit each including the normally closed contact of a different one of the associated contact mechanisms, a different one of the associated lever contacts, the associated control section, and the opposite rail of said stretch; a plurality of circuits for the second electromagnet of each timing unit each including one of the normally open contacts of a different one of the associated contact mechanisms, a different one of the associated lever contacts, the associated control section, and the opposite rail of said stretch; a relay, and a plurality of circuits for said relay each including one of said control sections, a different one of the associated lever contacts, a different one of the other normally open contacts of the contact mechanism of the associated timing unit and the rail of said stretch opposite to said control section, and means controlled by said relay for controlling said braking bar.

1'7. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and a normally open contact, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contact when said member is moved away from said one position a predetermined amount, an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position at a selected one of a plurality of predetermined speeds, an energizing circuit for said electromagnet including said control section, the opposite rail of said stretch and said normally closed contact; and an electroresponsive device controlled by said normally open contact.

18. In combination, a stretch of railway track, an'insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and a normally open contact, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contact when said member is moved away from said one position a predetermined amount, an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position at a selected one of a plurality of predetermined speeds, an energizing circuit for said electromagnet including said control section, the opposite rail of said stretch and said normally closed contact; and means controlled by said normally open contact for controlling the speed of a car traversing said stretch.

19. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and a normally open contact, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contact when said member is moved away from said one position a predetermined amount, an electromagnet, variable speed means effective when said electromagnet becomes energized for moving said member away from said one position, an energizing circuit for said electromagnet including said control section, the opposite rail of said stretch and said normally closed contact; and an electroresponsive device controlled by said normally open contact.

20. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a contact mechanism including a normally closed and two normally open contacts, means controlled by said member for operating said contact mechanism to open said normally closed contact and close said normally open contacts when said member is moved away from said one position a predetermined amount, a first electromagnet, variable speed means efiective when said first electromagnet becomes energized for moving said member away from said one position at a predetermined speed; an energizing circuit for said first electromagnet including said control section, the opposite rail of said stretch and said normally closed contact, a second electromagnet, means effective when said second electromagnet becomes energized for holding said member in the position which it then occupies; an energizing circuit for said second electromagnet including said control section, the opposite rail of said stretch and one of said normally open contacts; a car retarder associated with said stretch, and means controlled by the other normally open contact for controlling said car retarder.

21. In combination, a stretch of railway track, a member biased to one position, an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position at a predetermined speed, a plurality of contacts arranged to be operated by said member when said member is moved away from said position a predetermined distance, an energizing circuit for said electromagnet including one of said contacts, means controlled by a car traversing said stretch for controlling said circuit, and means controlled by another one of said contacts for controlling the speed of the car.

22. In combination, a stretch of railway track, a member biased to one position,'an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position at a predetermined speed, a plurality of contact mechanisms arranged to be selectively operated by said member in response to movement of said member away from said one position through difierent distances, a plurality of energizing circuits for said electromagnet each controlled by a difierent one of said contact mechanisms, means controlled by a car traversing said stretch for controlling said energizing circuits, and means controlled by said contact mechanisms for controlling the speed of said car.

23. In combination, a stretch of railway track, an insulated control section formed in one rail of said stretch, a member biased to one position, a plurality of contacts, means controlled by said member for operating said contacts when said member has beenmoved away from said one position a predetermined distance, an electromagnet, means effective when said electromagnet becomes energized for moving said member away from said one position in opposition to its bias at a predetermined speed, an energizing circuit for said electromagnet including said control section, the opposite rail of said stretch and one of said contacts, and means controlled by another of said contacts for controlling the speed of the car.

24. In combination, a stretch of railway track, a member which is constantly rotated, an electromagnet, a contact mechanism, means responsive to rotation of said member when said electromagnet is energized for operating said contact mechanism at the expiration of a predetermined time interval, means including said contact mechnism for at times energizing said electromagnet for a plurality of time intervals the duration of each of which depends upon the speed of a car traversing said stretch, and means controlled by said contact mechanism for controlling the speed of a car traversing said stretch.

JOHN W, LIVINGSTON. 

